Rules on 8.0.2

     Hi, I'm trying create the rule :

CREATE OR REPLACE RULE select_public_cliente AS ON SELECT TO public.cliente_tipo
  WHERE NOT EXISTS ( SELECT usesysid FROM pg_user left join pg_group on ( idx( grolist, usesysid ) > 0 )
                                         WHERE usename = current_user AND groname SIMILAR TO 'assinatura' )
  DO INSTEAD SELECT clt_dsc_tipo FROM public.cliente_tipo;

     Its to limit users to see only one column on table.  But I've the error:

ERROR:  event qualifications are not implemented for rules on SELECT

    The version is: PostgreSQL 8.0.2 on i686-pc-linux-gnu, compiled by GCC gcc (GCC) 3.3.5 (Debian 1:3.3.5-5)

    Any idea?

--
William Leite Araújo